Police officials say the incident occurred on February 11, 2010 in the 600 block of Edison Street.
Authorities say Alexander was with his girlfriend when he and his girlfriend got involved in a verbal and physical altercation with three females.
After an investigation by the Department's Internal Affairs Bureau and the Philadelphia District Attorney's Office, Alexander was charged with Criminal Conspiracy, Simple Assault and Recklessly Endangering Another Person.
Alexander is 22- years old and a 3- year veteran of the Department, assigned to the 24th District.
Philadelphia Police Commissioner Charles Ramsey has suspended Alexander for 30 days with the intent to dismiss.